A hot-water route that supplies hot water is generally provided with a heat storage tank. In the hot water route, a portion of water stored in the heat storage tank absorbs heat from a thermal output heat exchanger provided in a hot-water-heat-pump main unit, thereby performing temperature control (for example, Patent Literature 1).
In addition, the size of openings of control valves provided in a heat-source route and a coolant route, which lead to the hot-water heat pump, are controlled in accordance with the temperature of the hot-water route (for example, Patent Literature 2 and Patent Literature 4).